This invention relates to a method and an apparatus for its practice, integrated in a carding machine, a roller card unit or a similar fiber processing machine. The apparatus is of the known type in which the staple (fiber length) in the fiber mass is measured at the output of the machine (hereafter carding machine), and regulation is effected based on the sensed signals.
In a known process as disclosed in published European Patent Application No. 0 410 429, at the output of the carding machine the staple is measured; the measured values must correspond to precisely defined criteria. If it is not feasible to maintain such values within the predetermined magnitudes by regulating the carding machine, an attempt is first made to improve such values by setting the fine cleaning machine anew. If again, such an attempt is unsuccessful, it is necessary to change the mixing ratio which has to be performed by an appropriate control of the bale opener; this also affects the bale stock. In such a process the staple is measured only at the output of the carding machine. It is a disadvantage of such an arrangement that an accurate prediction concerning the shortening of staple by the carding machine is not possible. It is a further drawback that in the known process the basic assumption is that an improvement of the staple in the carding machine itself is not possible, but can be remedied essentially only by changing the mixing ratio.